In recent years, particularly on the west coast of Canada and the United States, it has become common practice to raise salt water fish, and notably salmon, in enclosures installed in suitable salt water coastal environments, commonly called fish or salmon farms. Such farms are of substantial size and rear thousands of salmon per year. A common problem associated with raising such large numbers of salmon is to conveniently store and handle the large quantities of food that the fish eat each day. For example, a typical salmon farm operation may require several tons of fish feed per day to satisfy the appetites of the rapidly growing fish. Handling fish food in bulk, typically pelletized or liquid fish feed, requires not only suitable, convenient and inexpensive ways to store such large quantities of such fish food but mechanisms must be devised so that the food can be readily and cheaply supplied to the fish. One method of dealing with these problems is to locate large floating fish feed sheds, scows, barges or silos adjacent the fish farm. These vessels are extremely expensive, tilt when being unloaded, and must be designed to minimize operational problems in rough waters.
The technology involved in fish farming, and principally salmon farms, is currently in a strong stage of development. It has been determined, for instance, that high quality feed and proper nutrition are extremely important to maintaining fish health and minimizing mortality rates. Proper fish nutrition improves the fish's resistance to disease and other problems which contribute to high mortality rates. It is thus an important factor to be able to store and readily supply to the fish large quantities of bulk high quality fish feed.
Recently, a liquid fish food emulsion which is stored on site in bulk containers and which, at fish feeding time, is blended on site in a hopper with a dry fish food admixture to form a soft pellet like material, has been used successfully as a fish farm food. The material is pumped directly to the fish pens. This type of fish food has been shown to increase salmon growing rates up to two fold over a twenty month rearing period compared to previous conventional fish feeding systems.